


Saturday Morning Sex

by PineTrain



Category: Gravity Falls
Genre: F/M, Wake-Up Sex, pinecest - Freeform
Language: English
Status: Completed
Published: 2017-07-11
Updated: 2017-07-11
Packaged: 2018-12-01 00:47:13
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,340
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11475087
Author URL: https://archiveofourown.org/users/PineTrain/pseuds/PineTrain





	Saturday Morning Sex

“Nnnnhhhmmmm…..”

Mabel’s groan was as incoherent as her own thoughts. Only vaguely awake at the moment, she barely registered the soft feeling of the pillow her face was shoved into. It was a nice sensation, so she nuzzled into it, rubbing her cheeks in small circles so as to feel it on as much of her skin as possible.

Everything was foggy, but she thought she might be awake. She wasn’t quite sure, since she was still following every instinct without question. She stretched without thinking, scratched without thinking, slid her hand over her skin without thinking. They all felt wonderful, but if her decision making wasn’t coherent, it did raise questions about her true wakefulness. Not that she asked them, prefering to instead bask in warmth spreading with every move she made.

Mabel breathed hotly against her pillow, tingles skittering through her skin as faint memories of a nigh-forgotten dream rose from the recesses of her mind. She’d been doing something in it, but she wasn’t sure what thing it was. She had loved it, she knew that at least. Perhaps too much since the heat within seemed to have awakened her from such a lovely experience.

Her hand slid into her shirt to run a small circle around her burning core before slipping into her pajama shorts. Her hand hovered just over her skin and she nipped at the fabric of the pillow as she struggled to grab hold of what had happened in the dream. She longed so much to use her fingers to find the release her body increasingly demanded, but she had to find that memory first. Her mind was too fuzzy to explain why she couldn’t masturbate to the thought of something else, so she sat in hellish limbo, a prisoner to her own impossible demands.

A car engine started outside, and Mabel thrust herself up into a seated position. The distraction provided a moment of lucidity and she scrambled to her blinds, peering through just in time to catch sight of her parents leaving the house. It was their biweekly shopping run to CostNo(thing). They’d be gone for hours, leaving just her and…

Dipper. It’s amazing the things one forgets when half asleep. Not just dreams, but the fact that they involved your significant brother, even though you’ve been secretly fucking him for two months now. Mabel’s breath started quickening again as bits of the dream finally came back to her. The details were still smudged to hell, but she knew it involved him, it was hot, and they were now the only people in the house. She exited her room and headed to his with not a proper thought in her mind. She knew what she wanted, and she would work out the details once she was getting it.

And what details they would be. That was the closest thing to a logical thought Mabel had once she saw her brother. Sprawled on his back, one arm was holding a pillow to his head while the other lay across his stomach. His blanket only covered a single leg and about 2/3s his crotch. Maybe even a little less than that as his morning wood gently raised the cloth a millimeter or so above the skin. How considerate of him to sleep naked.  
  
Mabel locked her eyes on the small tent that bobbed periodically as she crept closer with her lower lip between her teeth. As much as she wanted to stop where it was, she passed on so she could lean over her brother’s face. She watched the cute, subtle twitches he made while he slept, wondering if his dream was as erotic as hers had been or if it were just something inane. She pecked his lips lovingly, her own drifting downwards as she pulled away.

She wouldn’t need to wonder about his dreams if she applied a little real world inspiration to make them match hers. Using her nose to brush the blanket down, she felt his hardness slip up her cheek and shivered at the feeling of it bobbing gently against her. Mabel lightly tapped her fingers along its base, a lap of her tongue matching the force on the other side. She pushed lightly on his member from both directions and slowly dragged upwards inch by inch until she reached the head.

It slipped over her lips and into her mouth. Mabel immediately ran her tongue in a wet circle while her hand fell to wrap his shaft. Pausing a second, she felt another tingle of excitement shoot through her when Dipper twitched inside her mouth, a quiet moan escaping him. She couldn’t draw this out, her desire was too intense. She thrust her head down to engulf him in two quick movements, lubing him with her saliva as best she could.

Standing up, Mabel flung a leg over him and sat in his lap, wet dick between her legs. Impatience pounding in her blood, she held his member against her body as she rose, gasping once when the tip slipped over her hole, then again as she sank it into her. Her eyes fluttered, the feeling of fullness still somewhat new to her. She took a moment to acclimate before she began indulging further.

A thrust interrupted her before she could, though. Mabel sucked in air in surprise at how he could still somehow get even deeper inside her with the move. Another followed, and she squeaked aloud. Glancing down, she saw Dipper’s face contorted a bit. It didn’t look painful, but it didnt look concious either. Perhaps she had indeed affected his dream. Another thrust eliminated any desire for further speculation and she decided to take things into her own hands.

As he pulled back, Mabel shifted up, then dropped back down. She soon commanded the tempo, Dipper falling in line and matching her move for move. She moaned loudly in happiness as the itch she’d felt since waking up was finally getting scratched. One eye squinted closed to focus on the pleasure coursing through her, while the other barely stayed open to watch Dipper’s face.

His own eyes flickered into cognition as he awoke. His hips didn’t stop moving, but they lost their instinctive match to her own, the two now slapping haphazardly against each other. Mabel was pleased to have him awake, but there was a definite sense of disappointment when their mismatch interrupted the momentum of their connection.

Dipper grunted and shot his arms up her back to pull Mabel’s chest to his. Surprised, she followed him like a lever, hips raising from his just as their chests made contact, faces a half inch apart. This must’ve been his intent, because Mabel had no chance of responding before he slammed up and filled her in an instant. Her mind shuddered, a brief understanding of what was to come weedling through the fog when his fingers moved to hold her in position.

Once. Twice. Three, then four, then five times. Dipper shot his hips up into hers over and over, his hands keeping her steady. Mabel didn’t mind losing control since it let her focus more on the feeling of having her brother fuck her so intensly. She gasped aloud, a trickle of drool sneaking out the corner of her mouth.

“F-fuck! M-m-mabel!” Dipper grunted.

She instantly fell aside him so her lips were by his ear. “Give it to me! Cum in me!” she hissed, her eyes rolling up into her head as he complied. They stayed like that for a short while, then she collapsed atop him.

The twins didn’t last long in that position. Exhausted as they were, they shared a kiss, then cuddled and fell asleep. When they awoke, Dipper would worry over fear of discovery and Mabel would react with nonchalance, much as they always did with less expected moments in their unconventional relationship. In the end, though, they would both be happy about whatever happened in Mabel’s dream that got her so horny in the morning.


End file.
